Notices
General Boating Discussion

Minimum Engine Spacing

Thread Tools
 
Old 10-14-2007 | 07:05 AM
  #1  
Thread Starter
Registered
 
Joined: Aug 2007
Posts: 52
Likes: 0
From: Old Saybrook, CT
Default Minimum Engine Spacing

I have an old cig with the drive spacing at 25 1/4". I curious if anyone knows if a pair of small blocks would fit. They would replace a pair if I-6's. Thanks for any help.
knollwoodworker is offline  
Reply
Old 10-14-2007 | 04:08 PM
  #2  
Registered
 
Joined: Jan 2004
Posts: 3,682
Likes: 4
From: Boca Raton, FL
Default

Are you measuring prop shaft center to prop shaft center or distance between the transom plates?

Big blocks work on 36" centers in side-by-side applications. Small blocks will work on slightly less, but you may be limiting your exhaust choices.

Staggered engines usually end up on 18" centers and a short stagger about 22" centers.

From your post I suspect you're talking about an old 28' Cigarette that had the Chevy 250 cu.in. 6 cylinder engines with Alpha drives. Yes?
Edward R. Cozzi is offline  
Reply
Old 10-14-2007 | 05:29 PM
  #3  
Thread Starter
Registered
 
Joined: Aug 2007
Posts: 52
Likes: 0
From: Old Saybrook, CT
Default

Close, it's a 24' and it has 6 cyl 165hp engines. I measured the distance between the transom plates.
knollwoodworker is offline  
Reply
Old 10-14-2007 | 05:30 PM
  #4  
DirtyMoney's Avatar
Registered
 
Joined: May 2003
Posts: 3,025
Likes: 29
From: Murrayville, GA
Default

Measure from prop shaft to prop shaft.
DirtyMoney is offline  
Reply
Old 10-14-2007 | 07:16 PM
  #5  
Registered
 
Joined: Jan 2004
Posts: 3,682
Likes: 4
From: Boca Raton, FL
Default

Easier yet is to measure grease fitting to grease fitting in the top of the outer transom plates, if so equipped.
Edward R. Cozzi is offline  
Reply
Old 10-15-2007 | 04:29 PM
  #6  
Thread Starter
Registered
 
Joined: Aug 2007
Posts: 52
Likes: 0
From: Old Saybrook, CT
Default

25 1/4 was the distance between grease fittings.
knollwoodworker is offline  
Reply
Old 10-15-2007 | 04:46 PM
  #7  
Registered User
 
Joined: Oct 2003
Posts: 9,495
Likes: 6
Default

32 is usually standard small-block spacing. With Merc manifolds, you have a couple inches. With Crusaders, they just about touch.
Chris Sunkin is offline  
Reply
Old 10-15-2007 | 05:25 PM
  #8  
littledcsrodshop's Avatar
Registered
 
Joined: Apr 2005
Posts: 2,197
Likes: 3
From: TN
Default

I know you can atleast go 31" centers ( propshaft ) on small blocks with Gil manifolds. You may even be able to squeeze another inch or so.

I have a buddy that has an older 28 cig. small block boat with stock exhaust & although I am not sure what the centers are I know that the manifolds are all but touching. so some of the guys in the cig. section should be able to tell what the tightests you can go is. I would post your question in there also if you havn't already..
littledcsrodshop is offline  
Reply
Old 10-15-2007 | 07:43 PM
  #9  
Top Banana's Avatar
Registered
20 Year Member
 
Joined: Nov 2004
Posts: 3,674
Likes: 250
From: Rhode Island summer, Florida winter
Default

32 inch centers with twin 280 TRS packages in a 24 race boat.

This is the exact same hull you have with a 24 Cigarette.


www.bananaboatco.com
Attached Thumbnails Minimum Engine Spacing-cmc0001-small-.jpg  

Last edited by Top Banana; 10-15-2007 at 07:47 PM.
Top Banana is offline  
Reply
Old 10-15-2007 | 09:58 PM
  #10  
hunster's Avatar
Registered
 
Joined: Feb 2005
Posts: 1,626
Likes: 0
From: oceanport nj
Default

Measured my small block setup in the scarab. Propshaft measurement was 31" . Measured @ the dimple in the top of the gimbal ring and it was 31" , thought I had the drives toed but I guess not . Measured between the transoms , 19" . I can barely get my hand between the stock merc manifolds. Alpha transom / drive setup.
hunster is offline  
Reply


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.